Diarrhea is a common complication among HIV infected individuals. Cryptosporidium parvum is the most common parasite-causing diarrhea in immunocompromised patient, mainly affect children and elderly individuals. The study is designed to know the prevalence of Cryptosporidiosis in HIV patients and non-HIV patients attending our hospital. Materials and Methods- We examined 57 stool samples from HIV infected patients with diarrhea and 754 faecal samples from non-HIV patients with diarrhea by modified Ziehl-Neelsen and Giemsa staining. Findings- 22 stool samples were positive for oocyst of Cryptosporidium in HIV infected patients and 19 were positive in Non-HIV patients. All 41 stool samples were positive for Cryptosporidium by modified Ziehl-Neelsen method and 39 by Giemsa staining. Conclusions- There is a high prevalence of Cryptosporidiosis in HIV infected patients and simple modified ZN staining can detect oocyst in stool sample.